How to avoid background image distortion?

Question

JavaScript

The problem is the following. The site has a large background image (1mb). When viewed on mobile, the background image is slightly distorted. This happens when scrolling the site. At first I sinned on chrome. I thought that he was doing this under androgen. Then I turned off everything that was possible, leaving only the background image. In this scenario, there were no errors. Then I connected jquery and then the problem repeated.
jQuery using 1.11.3. You can try an earlier version or maybe there are some other options how to fix it. The problem only occurs on mobile. Everything is fine on PC.
I'm testing here

Answer 1

The following helped in my case:

@media screen and (max-width: 1170px) {
body {
    background:url("../img/fon.jpg";)  center 0 no-repeat;
}
}